x=$c
s=0
while [ $x -gt 0 ]; do
        r=`expr $x % 10`
        s=`expr $s + $r * $r * $r`
        x=`expr $x / 10`
done

if [ $s -eq $c ]; then
	echo "It is an armstrong number"
else
	echo "It is not an armstrong number"
fi